1. Field of the Invention
The present invention relates to a chip electronic component such as a multi-layer ceramic capacitor, and more particularly, to a structure of an external electrode thereof.
2. Description of Related Art
A chip electronic component such as a multi-layer ceramic capacitor generally includes a cuboid main body and an external electrode. The main body has internal electrodes therein. The external electrode is formed on an outer surface of the main body, and is electrically connected to the internal electrodes. A shape, a quantity, and a forming position of the external electrode vary depending on a type of the chip electronic component. In a typical multi-layer ceramic capacitor, for example, the external electrodes are formed on two end surfaces of the cuboid main body, partially covering side surfaces that are adjacent to these end surfaces. As a typical method for forming the external electrode, the following method is known: coating the surface of the main body with a paste that is mainly made of Cu, Ni, Ag, or the like by a dipping method; firing the main body with the paste; and forming a single or a plurality of plating layers by electrolytic plating (Patent Document 1). The plating layers are provided for improving wettability and preventing solder from dissolving the electrode. As a specific example of such plating layers, an Ni film may be formed on the electrode layer that has been formed by paste coating and firing, and the Sn film may be formed on the Ni film in which the Ni film is for preventing the solder from dissolving the electrode, and the Sn film is for improving the solder wettability and for preventing oxidation of the Ni film.